1、What is Software Quality Assurance? Software QA involves the entire software development PROCESS - monitoring and improving the process, making sure that any agreed-upon standards and procedures are followed, and ensuring that problems are found and dealt with. It is oriented to prevention. (See the
2、 Bookstore sections Software QA category for a list of useful books on Software Quality Assurance.) Return to top of this pages FAQ list What is Software Testing? Testing involves operation of a system or application under controlled conditions and evaluating the results (eg, if the user is in inter
3、face A of the application while using hardware B, and does C, then D should happen). The controlled conditions should include both normal and abnormal conditions. Testing should intentionally attempt to make things go wrong to determine if things happen when they shouldnt or things dont happen when
4、they should. It is oriented to detection. (See the Bookstore sections Software Testing category for a list of useful books on Software Testing.) Organizations vary considerably in how they assign responsibility for QA and testing. Sometimes theyre the combined responsibility of one group or individu
5、al. Also common are project teams that include a mix of testers and developers who work closely together, with overall QA processes monitored by project managers. It will depend on what best fits an organizations size and business structure. Return to top of this pages FAQ list What are some recent
6、major computer system failures caused by software bugs? A September 2006 news report indicated problems with software utilized in a state governments primary election, resulting in periodic unexpected rebooting of voter checkin machines, which were separate from the electronic voting machines, and r
7、esulted in confusion and delays at voting sites. The problem was reportedly due to insufficient testing. In August of 2006 a U.S. government student loan service erroneously made public the personal data of as many as 21,000 borrowers on its web site, due to a software error. The bug was fixed and t
8、he government department subsequently offered to arrange for free credit monitoring services for those affected. A software error reportedly resulted in overbilling of up to several thousand dollars to each of 11,000 customers of a major telecommunications company in June of 2006. It was reported th
9、at the software bug was fixed within days, but that correcting the billing errors would take much longer. News reports in May of 2006 described a multi-million dollar lawsuit settlement paid by a healthcare software vendor to one of its customers. It was reported that the customer claimed there were
10、 problems with the software they had contracted for, including poor integration of software modules, and problems that resulted in missing or incorrect data used by medical personnel. In early 2006 problems in a governments financial monitoring software resulted in incorrect election candidate finan
11、cial reports being made available to the public. The governments election finance reporting web site had to be shut down until the software was repaired. Trading on a major Asian stock exchange was brought to a halt in November of 2005, reportedly due to an error in a system software upgrade. The pr
12、oblem was rectified and trading resumed later the same day. A May 2005 newspaper article reported that a major hybrid car manufacturer had to install a software fix on 20,000 vehicles due to problems with invalid engine warning lights and occasional stalling. In the article, an automotive software s
13、pecialist indicated that the automobile industry spends $2 billion to $3 billion per year fixing software problems. Media reports in January of 2005 detailed severe problems with a $170 million high-profile U.S. government IT systems project. Software testing was one of the five major problem areas
14、according to a report of the commission reviewing the project. In March of 2005 it was decided to scrap the entire project. In July 2004 newspapers reported that a new government welfare management system in Canada costing several hundred million dollars was unable to handle a simple benefits rate i
15、ncrease after being put into live operation. Reportedly the original contract allowed for only 6 weeks of acceptance testing and the system was never tested for its ability to handle a rate increase. Millions of bank accounts were impacted by errors due to installation of inadequately tested softwar
16、e code in the transaction processing system of a major North American bank, according to mid-2004 news reports. Articles about the incident stated that it took two weeks to fix all the resulting errors, that additional problems resulted when the incident drew a large number of e-mail phishing attack
17、s against the banks customers, and that the total cost of the incident could exceed $100 million. A bug in site management software utilized by companies with a significant percentage of worldwide web traffic was reported in May of 2004. The bug resulted in performance problems for many of the sites
18、 simultaneously and required disabling of the software until the bug was fixed. According to news reports in April of 2004, a software bug was determined to be a major contributor to the 2003 Northeast blackout, the worst power system failure in North American history. The failure involved loss of e
19、lectrical power to 50 million customers, forced shutdown of 100 power plants, and economic losses estimated at $6 billion. The bug was reportedly in one utility companys vendor-supplied power monitoring and management system, which was unable to correctly handle and report on an unusual confluence o
20、f initially localized events. The error was found and corrected after examining millions of lines of code. In early 2004, news reports revealed the intentional use of a software bug as a counter-espionage tool. According to the report, in the early 1980s one nation surreptitiously allowed a hostile
21、nations espionage service to steal a version of sophisticated industrial software that had intentionally-added flaws. This eventually resulted in major industrial disruption in the country that used the stolen flawed software. A major U.S. retailer was reportedly hit with a large government fine in
22、October of 2003 due to web site errors that enabled customers to view one anothers online orders. News stories in the fall of 2003 stated that a manufacturing company recalled all their transportation products in order to fix a software problem causing instability in certain circumstances. The compa
23、ny found and reported the bug itself and initiated the recall procedure in which a software upgrade fixed the problems. In August of 2003 a U.S. court ruled that a lawsuit against a large online brokerage company could proceed; the lawsuit reportedly involved claims that the company was not fixing s
24、ystem problems that sometimes resulted in failed stock trades, based on the experiences of 4 plaintiffs during an 8-month period. A previous lower courts ruling that “.six miscues out of more than 400 trades does not indicate negligence.“ was invalidated. In April of 2003 it was announced that a lar
25、ge student loan company in the U.S. made a software error in calculating the monthly payments on 800,000 loans. Although borrowers were to be notified of an increase in their required payments, the company will still reportedly lose $8 million in interest. The error was uncovered when borrowers bega
26、n reporting inconsistencies in their bills. News reports in February of 2003 revealed that the U.S. Treasury Department mailed 50,000 Social Security checks without any beneficiary names. A spokesperson indicated that the missing names were due to an error in a software change. Replacement checks we
27、re subsequently mailed out with the problem corrected, and recipients were then able to cash their Social Security checks. In March of 2002 it was reported that software bugs in Britains national tax system resulted in more than 100,000 erroneous tax overcharges. The problem was partly attributed to
28、 the difficulty of testing the integration of multiple systems. A newspaper columnist reported in July 2001 that a serious flaw was found in off-the-shelf software that had long been used in systems for tracking certain U.S. nuclear materials. The same software had been recently donated to another c
29、ountry to be used in tracking their own nuclear materials, and it was not until scientists in that country discovered the problem, and shared the information, that U.S. officials became aware of the problems. According to newspaper stories in mid-2001, a major systems development contractor was fire
30、d and sued over problems with a large retirement plan management system. According to the reports, the client claimed that system deliveries were late, the software had excessive defects, and it caused other systems to crash. In January of 2001 newspapers reported that a major European railroad was
31、hit by the aftereffects of the Y2K bug. The company found that many of their newer trains would not run due to their inability to recognize the date 31/12/2000; the trains were started by altering the control systems date settings. News reports in September of 2000 told of a software vendor settling
32、 a lawsuit with a large mortgage lender; the vendor had reportedly delivered an online mortgage processing system that did not meet specifications, was delivered late, and didnt work. In early 2000, major problems were reported with a new computer system in a large suburban U.S. public school distri
33、ct with 100,000+ students; problems included 10,000 erroneous report cards and students left stranded by failed class registration systems; the districts CIO was fired. The school district decided to reinstate its original 25-year old system for at least a year until the bugs were worked out of the
34、new system by the software vendors. A review board concluded that the NASA Mars Polar Lander failed in December 1999 due to software problems that caused improper functioning of retro rockets utilized by the Lander as it entered the Martian atmosphere. In October of 1999 the $125 million NASA Mars C
35、limate Orbiter spacecraft was believed to be lost in space due to a simple data conversion error. It was determined that spacecraft software used certain data in English units that should have been in metric units. Among other tasks, the orbiter was to serve as a communications relay for the Mars Po
36、lar Lander mission, which failed for unknown reasons in December 1999. Several investigating panels were convened to determine the process failures that allowed the error to go undetected. Bugs in software supporting a large commercial high-speed data network affected 70,000 business customers over
37、a period of 8 days in August of 1999. Among those affected was the electronic trading system of the largest U.S. futures exchange, which was shut down for most of a week as a result of the outages. In April of 1999 a software bug caused the failure of a $1.2 billion U.S. military satellite launch, t
38、he costliest unmanned accident in the history of Cape Canaveral launches. The failure was the latest in a string of launch failures, triggering a complete military and industry review of U.S. space launch programs, including software integration and testing processes. Congressional oversight hearing
39、s were requested. A small town in Illinois in the U.S. received an unusually large monthly electric bill of $7 million in March of 1999. This was about 700 times larger than its normal bill. It turned out to be due to bugs in new software that had been purchased by the local power company to deal wi
40、th Y2K software issues. In early 1999 a major computer game company recalled all copies of a popular new product due to software problems. The company made a public apology for releasing a product before it was ready. The computer system of a major online U.S. stock trading service failed during tra
41、ding hours several times over a period of days in February of 1999 according to nationwide news reports. The problem was reportedly due to bugs in a software upgrade intended to speed online trade confirmations. In April of 1998 a major U.S. data communications network failed for 24 hours, crippling
42、 a large part of some U.S. credit card transaction authorization systems as well as other large U.S. bank, retail, and government data systems. The cause was eventually traced to a software bug. January 1998 news reports told of software problems at a major U.S. telecommunications company that resul
43、ted in no charges for long distance calls for a month for 400,000 customers. The problem went undetected until customers called up with questions about their bills. In November of 1997 the stock of a major health industry company dropped 60% due to reports of failures in computer billing systems, pr
44、oblems with a large database conversion, and inadequate software testing. It was reported that more than $100,000,000 in receivables had to be written off and that multi-million dollar fines were levied on the company by government agencies. A retail store chain filed suit in August of 1997 against
45、a transaction processing system vendor (not a credit card company) due to the softwares inability to handle credit cards with year 2000 expiration dates. In August of 1997 one of the leading consumer credit reporting companies reportedly shut down their new public web site after less than two days o
46、f operation due to software problems. The new site allowed web site visitors instant access, for a small fee, to their personal credit reports. However, a number of initial users ended up viewing each others reports instead of their own, resulting in irate customers and nationwide publicity. The pro
47、blem was attributed to “.unexpectedly high demand from consumers and faulty software that routed the files to the wrong computers.“ In November of 1996, newspapers reported that software bugs caused the 411 telephone information system of one of the U.S. RBOCs to fail for most of a day. Most of the
48、2000 operators had to search through phone books instead of using their 13,000,000-listing database. The bugs were introduced by new software modifications and the problem software had been installed on both the production and backup systems. A spokesman for the software vendor reportedly stated tha
49、t It had nothing to do with the integrity of the software. It was human error. On June 4 1996 the first flight of the European Space Agencys new Ariane 5 rocket failed shortly after launching, resulting in an estimated uninsured loss of a half billion dollars. It was reportedly due to the lack of exception handling of a floating-point error in a conversion from a 64-bit integer to a 16-bit signed integer. Software bugs caused the bank accounts of 823 customers of a m
